Yeah, the free listing is nice. Although it seems as if they're in a "beta testing" period, so don't be surprised if they get all "knotty" on you with pricing and contracts.
I found out about Wedding Wire about a month ago after meeting/booking a client that has their wedding page on it (they sent me their link so I'd know more about them before the consultation). I started with the free listing but upgraded to the featured one about two weeks ago, where you're listed on the top/first page.
Looks pretty legit so far although the budget of client varies. Good customer service. Easy to use interface although their gallery upload feature needs some work. They also give you a lot of ways to market yourself to brides and connect with other vendors. I've had five inquiries and in the midst of talking with three of them.